← Chrome 153 reference

v153 · privacy-sandbox · cookies · deprecation

Deprecate and Remove: Related Website Sets (RWS)

Chrome 153 begins the stepped removal of Related Website Sets (formerly First Party Sets), a Privacy Sandbox framework that allowed limited cross-site cookie access within declared site groups. Following Chrome's decision to maintain third-party cookies, RWS no longer serves its intended purpose and is being removed.

Deprecation / removal: This entry documents a feature that is being removed from Chrome. Sites relying on RWS-based cross-site cookie access should migrate to standard Storage Access API behaviour.

at a glance

Shipped inChrome 153 (Stepped rollout — deprecation begins)
StatusDeprecation / removal in progress
Standards position (Firefox)No signal
Standards position (Safari)No signal
ChromeStatus5194473869017088 — Deprecate and Remove: Related Website Sets (RWS)
Source: chromestatus.com/feature/5194473869017088

background

Related Website Sets (RWS), formerly First Party Sets, let site operators declare formal relationships between domains they control (e.g. example.com, example.co.uk, static.example.com). Chrome used these declarations to grant limited cross-site cookie access via the Storage Access API (SAA) and document.requestStorageAccessFor().

RWS was designed as a transitional mechanism for a web without third-party cookies. Following Google's announcement that Chrome will maintain third-party cookies, RWS is no longer needed for its intended use case and is being removed.

Source: chromestatus feature summary

what is removed

ComponentStatus
Related Website Sets declarations / membershipRemoved
SAA cross-site access granted via RWS membershipFalls back to standard SAA behaviour (requires user permission prompt)
document.requestStorageAccessFor() (rSAFor)Removed via separate intent
RWS-related Chrome Enterprise policiesDeprecated
chrome.privacy.relatedWebsiteSetsEnabled extension APIDeprecated

The Storage Access API itself continues to work; only the RWS-specific exemption path is removed. Without RWS, SAA requests from cross-site embeds go through the standard browser permission prompt flow.

Source: chromestatus feature summary

migration

Sites that used RWS to enable cross-site storage access should evaluate whether they still need cross-site access. If they do, the standard Storage Access API (without RWS) continues to work but requires explicit user permission. See the Storage Access API documentation for the standard flow.

Source: chromestatus feature summary

see also